Transportation and fate of cationic surfactant in river water

The degradation, sorption, transportation and material balance of cationic surfactants discharged from domestic waste into river water was studied. Ion-pair solid-phase extraction behavior showed that the sorption of cationic surfactants as an ion-pair with anionic surfactant onto river sediment was so strong that little cationic surfactant was found in the bulk water. Cationic surfactant was found in river sediment at more than 500 times higher concentration than that in the bulk water. The degradation of the cationic surfactant was very slow in river water and much slower in the sediment. A material balance of cationic surfactant was estimated for a river running through Toyama City by measuring the flow rate and the concentration of cationic surfactant in the water at several points. It was found that more than 30% of cationic surfactant introduced to the river was lost during the river running through ca. 3 km in 3 h. This reduction probably comes from a quick transfer of the cationic surfactant from river water to sediment and water weed by means of adsorption or precipitation with suspending solids.     

Assessing land use impacts on flood processes in complex terrain by using GIS and modeling approach

A distributed hydrologic modeling and GIS approach is applied for the assessment of land use impact in the Steinsel sub-basin, Alzette, Grand-Duchy of Luxembourg. The assessment focuses on the runoff contributions from different land use classes and the potential impact of land use changes on runoff generation. The results show that the direct runoff from urban areas is dominant for a flood event compared with runoff from other land use areas in this catchment, and tends to increase for small floods and for the dry season floods, whereas the interflow from forested, pasture and agricultural field areas contributes to the recession flow. Significant variations in flood volume, peak discharge, time to the peak, etc., are found from the model simulation based on the three hypothetical land use change scenarios.     

Application of a checklist for quality assistance in environmental modelling to an energy model

Large, complex energy models present considerable challenges to develop and test. Uncertainty assessments of such models provide only partial guidance on the quality of the results. We have developed a model quality assistance checklist to aid in this purpose. The model checklist provides diagnostic output in the form of a set of pitfalls for the model application. The checklist is applied here to an energy model for the problem of assessing energy use and greenhouse gas emissions. Use of the checklist suggests that results on this issue are contingent on a number of assumptions that are highly value-laden. When these assumptions are held fixed, the model is deemed capable of producing moderately robust results of relevance to climate policy over the longer term. Checklist responses also indicate that a number of details critical to policy choices or outcomes on this issue are not captured in the model, and model results should therefore be supplemented with alternative analyses.     

基于N，N─二甲基苯胺与NO_2~－─对氨基苯磺酸重氮盐的偶联反应示波极谱法测定NO_2~－

报道了利用Ｎ，Ｎ─二甲基苯胺为偶联试剂的Ｃｒｉｅｓｓ反应以示波极谱法测定ＮＯ_２~－的测试方法。在拟定的实验条件下，ＮＯ_２~－在４．０×１０~－３～４．８×１０~－１μｇ／ｍｌ范围内与极谱波波高呈良好的线性关系。环境水测定的相对标准偏差小于ｌ％，回收率在９７％～１０１％之间。     

连续化学浸提法测定底泥中不同形态汞的探讨

本文提出用连续化学浸提法将底泥作连续五次抽提,根据不同形态汞的溶解度,将底泥中汞分为水溶性汞、酸溶性汞、碱溶性汞、硝酸溶汞、王水溶汞五个部分。对蓟运河沿岸的天化、茶淀和污水库底泥中汞作上述化学形态分析。用合成样品验证求回收率,认为对底泥中惰性汞的测定较热解法可靠,并发现底泥中腐殖质汞与惰性汞之间有相关关系。     

环境科学研究中两变量非线性相关时的线性回归方程

以环境科学研究两变量非线性相关的问题为对象，讨论建立线性回归方程的方法。有绝对误差均方和最小的最小二乘法、相对误差最小的新回归法。以简易的方法，建立相关性好、误差小的回归方程。介绍了两变量各种非线性相关时的线性回归方程在环境科学研究中的应用。     

区域环评中废水排放量的预测方法研究

阐述了区域环评污染物排放源强的预测原则,对区域开发活动中废水量和COD排放量的预测方法作了详细论述,并以温州滨海新区环评为例作了实证研究.     

寓资源环境保护于发展之中

本文从四个方面阐述了中国的环境与发展问题。要改善中国目前生态状况的关键在于树立生态道德观念，扭转贫困地区的面貌，寓资源环境保护于发展之中。     

基于生态功能考虑的西北干旱地区生态需水研究

在当前生态需水研究的基础上,选取植被盖度作为衡量绿洲生态功能的主要指标,根据植被盖度和侵蚀率之间的关系,从生态系统的需水机理出发,提出了基于生态功能考虑的西北干旱地区生态需水量计算方法.以额济纳绿洲为例,计算了2000年额济纳绿洲生态需水,并与额济纳绿洲不同时期的生态需水进行了对比分析.     

环境污染纠纷技术仲裁监测方法探讨

以某铝厂环境空气氟化物污染纠纷的技术仲裁监测为实例，总结出了一套环境污染纠纷技术仲裁监测的工作程序和方法，从法律程序、技术路线、质量保证，监测指标体系等方面对环境污染纠纷技术仲裁监测工作如何开展进行了探讨。